#include <iostream>

using std::cout;
using std::endl;

class Base {
public:
    Base(){ cout << "Base()" << endl; }
private:
    long _base;
};

class Derived
: public Base
{
public:
    Derived(long derived)
        // : Base()  //自动调用Base的默认无参构造
        : _derived(derived)
    { cout << "Derived(long)" << endl; }

    long _derived;
};

void test() {
    Derived d(1);
}

int main()
{
    test();
    return 0;
}

